In vitro effects of chorionic gonadotropin hormone on human adipose development

Abstract

It is well known that pregnancy is associated with fat weight gain. However, the mechanisms whereby fat mass accumulation is controlled during this period are poorly understood. Therefore, we attempted to determine whether human chorionic gonadotropin (HCG), in vitro, influences human adipose tissue development and/or metabolism. For the first time, HCG/LH receptor was characterized in human adipose cells. We also demonstrated that physiological concentrations of HCG, while unaltering both lipolysis and expression of two markers of lipogenesis (FAS and ADD1) in human mature adipocytes, stimulate human preadipocyte growth via the activation of a protein kinase A-independent mitogen-activated protein kinase/c-fos signaling pathway. HCG also moderately increases the preadipocyte differentiation capacity as reflected by enhanced glycerophosphate dehydrogenase activity and expression of key adipogenic transcriptional factors (C/enhancer-binding protein a and peroxisome proliferatoractivated receptor g 2). Finally, HCG significantly stimulates the secretion of the proadipogenic factor, leptin, from human adipose tissue. Taken altogether, these data suggest that the proadipogenic effect of HCG in human preadipocytes contributes to explain why increased fat storage occurs during the first trimester of pregnancy.

Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin

“…Thus, Lappas et al (2005) reported that in human adipose tissue and placental tissues explants, exogenous leptin increased the secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, as had already been reported for human chorionic gonadotropin (hCG) in cytotrophoblasts (Chardonnens et al, 1999). Recent data has brought this regulatory pathway full circle by indicating that hCG exerts a proadi pogenic e ect in human preadipocytes by simulating leptin secretion (Dos Santos et al, 2007). Most signi cantly, the regulation of proin ammatory cytokines produced in the intrauterine environment, may suggest roles for leptin in regulating endometrial attachment (Schulz et al, 2009), modulating myometrial contractility, cervical ripening, and the rupture of conceptus membranes (Lappas et al, 2005), all of which signi cantly impact the processes associated with parturition.…”

High levels of chorionic gonadotrophin attenuate insulin sensitivity and promote inflammation in adipocytes

“…In a previous study, the CG/LHR was detected in human adipose tissue (Dos Santos et al 2007). In our study, we first analysed the expression of the CG/LHR in insulinsensitive cells (3T3-L1 adipocytes and C2C12 myoblasts) by RT-PCR.…”

“…CG has also been characterised as a novel angiogenic factor in human endothelial cells (Zygmunt et al 2002). Dos Santos et al (2007) reported that CG/LHR is expressed in human primary adipocytes and that the proadipogenic effect of CG in human preadipocytes leads to the increased fat storage that occurs during the first trimester of pregnancy. In this study, we first confirmed that mature 3T3-L1 adipocytes and C2C12 CG activates the IKKB/NF-kB signalling pathway in 3T3-L1 adipocytes.…”

“…Accumulating evidence indicates that several non-gonadal tissues contain low levels of functional CG/LHR and that the non-gonadal actions of LH/CG are physiologically important (Rao 2001, Abdallah et al 2004. Results described in previous reports have indicated that CG/LHR is expressed in human primary adipocytes and 3T3-L1 adipocytes, CG treatment influences preadipocyte differentiation and leptin secretion (Sivan et al 1998, Dos Santos et al 2007). However, up till now, it remains unclear whether the surge in CG secretion with GDM contributes to IR and inflammation through functional CG/LHR in non-gonadal tissues.…”

Involvement of leptin in the molecular physiology of the placenta

“…Previous data have demonstrated the involvement of both C/EBP and Sp1 transcription factors in the regulation of leptin gene in adipocytes (Mason et al 1998). Moreover, the C/EBP transcription factor expression was reported to be regulated by hCG in the follicular development (Sirois & Richards 1993), in rat primary cultures of Leydig cells and in human adipose cells (Nalbant et al 1998, Dos Santos et al 2007.…”